The wireless resources in the third generation mobile communication system, for example, Time-Division Synchronization Code Division-Multiple-Access (TD-SCDMA) system, are controlled by a Radio Network Controller (RNC). Based on the resource capacity information reported by each Node-B (base station), the RNC decides how to control the wireless resources. Therefore, the wireless resources can be well controlled if the Node-B can provide the RNC with accurate and sufficient resource capacity information.
The Node-B reports wireless resources information to the RNC according to the resource state indicating message and the resource audit response message through the lub interface.
While the resources in a sub zone have changed, the Node-B will report to the RNC using the resource state-indicating message, as shown in FIG. 1.
The Node-B will audit the resource in the sub zone and report it to the RNC further on after receiving a request for resource audit issued by the RNC, as shown in FIG. 2, so that the resource information of the Node-B conform to that of RNC.
The conventional resource state indicating message and resource audit response message comprise UL Capacity Credit and DL (Global) Capacity Credit of Node-B.
In TD-SCDMA system (a single-carrier system), the UL Capacity Credit and the DL (Global) Capacity Credit are simulated by the Node-B into code channels while spreading factor equals 16. For example, a sub zone covered by the Node-B supports K number of timeslots, wherein m number of timeslots is used as uplink timeslots and n number of timeslots is used as downlink timeslots, and the code channels for uplink and downlink timeslots are referred to as U1CodeNumi(i=1,Λ,m) and D1CodeNumj(j=1,Λ,n), respectively, thus the parameters m and n should be confined by the following equations:K=m+n≦7  (1)
and the UL Capacity Credit and the DL (Global) Capacity Credit are computed by the following formulas:
                              UL          ⁢                                          ⁢          Capacity          ⁢                                          ⁢          Credit                =                              ∑                          i              =              1                        m                    ⁢                                          ⁢                      U            ⁢                                                  ⁢            1            ⁢                          CodeNum              i                                                          (        2        )                                          DL          ⁢                                          ⁢          Capacity          ⁢                                          ⁢          Credit                =                              ∑                          j              =              1                        n                    ⁢                                          ⁢                      D            ⁢                                                  ⁢            1            ⁢                          CodeNum              j                                                          (        3        )            
In practical application, however, the number of timeslots supported by a sub zone may be less than 7 after the sub zone is established for some of the timeslots are unusable due to physical resource problems. The information about timeslots TS1, TS2 . . . TS7 could not be included in the UL Capacity Credit and the DL Capacity Credit computed according to the formulas (2) and (3). Referring to FIG. 3, the RNC can't properly obtain either those timeslots unusable or resource capacity information of each timeslot after the UL Capacity Credit and the DL Capacity Credit are reported to the RNC through an Iub interface. Therefore, the resource capacity information between the RNC and the Node-B are of inconsistency.
When a radio link being established, the RNC has to assign some timeslots through Node-B to bear the radio link. Since the RNC doesn't know the availability of each timeslot according to the conventional method of management for wireless resources, the establishment for a radio link will break down if the RNC assigns an unavailable timeslot. Furthermore, a radio link is usually born on several timeslots. The failure for the establishment of radio link will occur once one of the timeslots is unusable. Under the situation, the success rate for the establishment of radio link for the conventional method is low, and the system access performance is badly affected.
At present, the capacity of the TD-SCDMA system is relatively lower than that of the WCDMA system. To increase the capacity of TD-SCDMA system, it is no doubt to be a good manner for using multi-carrier frequencies to cover a cell/sector.
Only may a carrier frequency be chosen to send pilot signal and broadcast message in such a cell/sector covered by multi-carrier frequencies in order to decrease the broadcast channel interference among different carrier frequencies and increase system efficiency. Thus, all carrier frequencies use the same broadcast. For example, there are N numbers of carrier frequencies to cover a cell/sector and to be labeled carrier frequency 1, 2 . . . N respectively. If the carrier frequency 1 is used to send pilot signal and broadcast message, then the others will not be used to send pilot signal and broadcast message any longer. The carrier frequency 1 is called a main carrier frequency, and the others carrier frequencies 2 . . . N are called sub carrier frequency. The main carrier frequency and the sub carrier frequencies use the same scrambling and basic midamble, the same common control channel and have the same configuration of switch point for uplink and downlink. A mobile terminal can obtain system information and frequency configuration of other sub carrier frequencies by searching for the main carrier frequency.
According to the multi-carrier system of the prior art, the resource capacity information for the Node-B is in basis of that of the whole cell, but not for each carrier frequency. Now referring to FIGS. 1 and 2, the Node-B reports to the RNC using the resource state indicating message and the resource audit response message respectively. Thus, the RNC can obtain the resource capacity information of the whole cell from the Node-B, as shown in FIG. 3. However, the resource capacity information between the RNC and the Node-B are of inconsistency, as the resource information of each carrier frequency in the cell is not reported to the RNC.
It is a big problem for the method of reporting the information of the prior art that the RNC cannot be informed once any one of sub carrier frequencies is broken down. As a result, the failure of establishment for radio link will occur as the RNC may still distribute service channel on the sub carrier frequency to be broken down, whereas system access performance may be affected from it badly.